The Philadelphia cheesesteak origins, which has become, a beloved symbol of the City of Brotherly Love, was born out of boredom with hot dogs rather than from a great culinary revelation, writes Tom Burson for National Geographic.

In 1930, Italian-American Pat Olivieri owned a hot dog cart in South Philly. One day, he decided he wanted something different. Instead of the usual wiener sausages, he ordered some scraps of beef from a butcher. He then grilled the beef with onions and scooped it into a hot dog bun. A cab driver who was passing by thought it looked good, so he ordered the same thing.

According to Pat’s King of Steaks, which has grown from a cart into a restaurant, after finishing the sandwich, the driver said, “Hey… forget ’bout those hot dogs, you should sell these.”

The cheese was added to the mix a decade later when ‘Cocky Joe’ Lorenza, the manager of Pat’s restaurant, put a few slices of provolone on the sandwich. The final product caught on like wildfire.

Today, the cheesesteak has spread far from its humble cart origins and is now being served even in fine-dining restaurants throughout the city.

Read more about the Philly cheesesteak in National Geographic.